Aerial propeller



E. KLUMPP.

AERIAL PROPELLER.

APPLIBATION man NOV. 23. ms.

Patented Feb. 15,1921.

2 SHEETS-SHEET l- Jaw 1g M11101".

v iorzu g E. KLUMPP.

AERIAL PROPELLER.

APPLICATION FILED uov.'23. ma.

1,368,732. Patented Feb. 15,1921.

2 SHEETS-SHEET 2.

PATENT OFFICE.

EMIL KLUMPP, OF BUFFALO, NEW YORK.

AERIAL PBOPELLEB.

Specification of Letters Patent.-

Patented Feb. 15, 1921.

Application filed November 23, 1918. Serial No. 263,878.

T 0 all whom it may concern:

Be it known that I, EMIL KLUMPP, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Aerial Propellers, of which the following is a specification.

This invention relates to propellers, and more particularly to propellers for use on aeroplanes, hydroaeroplanes, or other aircraft.

Propellers of the present day type are extremel bulky and heavy and are so constructed that the edges thereof become easily damaged, and when damaged are difficult to repair. Moreover, the blades of propellers as now constructed become easily warped, which results in a change of ltc of the blades and consequently a loss 0 efficiency.

One of the primary objects of my invention is the production of a propeller which is exceedingly light, yet durable, and which is so constructed that the pitch to which the blades are built is retained under all weather conditions.

Another object of m invention is the provision of a propel er which can be quickly and conveniently applied to the propeller shaft of the aeroplane, and which has a central portion onto which the outer portions of the blades are built, said central portion being adapted to form the inner ends of the two blades of the propeller.

Another object of my invention is the provision of a propeller having each of its blades provided. with a metal foundation forged or otherwise. fashioned to the desired pitch and onto which the wooden exterior layers or facing members are applied.

A further object of my invention is to provide a metallic foundation for the wooden exterior of the blades and to reinforce or stiffen said foundation, preferably in both transverse and longitudinal directions.

A further object of my invention is the provision of a propeller having blades so constructed that they may be formed exceedingly thin, yet be durable and have the exterior faces thereof formed to the pitch or changing transverse angle from their outer ends inwardly to assure powerful action when rotating in space.

A still further object is the provision of novel binding or sheathing means applied around the edge of each blade and the provision of novel means for securing said b1nd in or sheathing means in lace.

ith these and other ob ects in view, m invention consists in a propeller having an integral central portion onto which the outer portions of the propeller blades are built and which inner portion forms a portion of said propeller blades.

It also consists in a propeller having a metallic foundation onto which layers of wood are applied and which permits of using a comparatively thin layer of wood at each side of the metallic foundation.

It further consists in providing a metallic foundation reinforced or stiffened both transversely and longitudinally, and also in binding or sheathing the edge of the blade and in the novel manner of securing the binding or sheathing material thereto.

'It further consists in the construction, arrangement and combination of parts to be hereinafter described and more particularly pointed out in the subjoined claims.

In the drawings:

Figure 1 is a front elevation of a propeller constructed according to my invention, the whole being covered with suitable fabric or other material and painted or varnished so as to conceal all joints, or otherwise finished to conceal all joints thereon.

Fig. 2 is an enlarged front elevation of one-half of the ropeller, showingthe same as it appears be ore applying the fabric and the paint or varnish, or otherwise finishing the same.

Fig. 3 is a front elevation of one-half of the metallic foundation to which the wooden exterior or facing members of the propeller are applied.

Fig. 4 is a longitudinal section taken centrally through one-half of a pro eller, the section being indicated by t e ine 4-4,

Fig 5.

ig. 5 is an enlar ed transverse section taken on line 5-5, ig. 2

Fig. 6 is an enlarged transverse section taken on line 6-6, Fig. 3.

Fig. 7 is a further enlarged transverse section taken through a portion of line 55,

Fig. 3, to more clearly show the construction and application of the binding or sheathing means at the edges of the propeller blades.

Fig. 8 is a longitudinal section portion of the blade taken on Fig. 9 is a detached perspective View of the metallic central portion comprising the hub and the inner ends of the metallic foundation forming parts of the blades.

Fig. 10 is a transverse section through one of the wings of the propeller showing the same armored.

aving reference now to the drawings in detail, the numeral 10 designates a forged metallic member comprising a hub 11 and two oppositely-disposed arms 12. These arms are given the desired pitch which the inner or hub ends of the blades are to have, and they serve as part of the metallic founthrough a line 88,

- dation to which other parts or members of the blades are to be applied. The hub has an axial bore 12 which is to receive the propeller axle to be fastened therein in any approved manner. By thus constructing the hub, the usual wooden laminated hub is dispensed with, also the end plates or disks usually employed in conjunction with said inner portions 13 The two arms 12 of this metallic central member 10, as it may be termed, have their shaped or forged to form unbroken continuations of the exterior surfaces of the portions of the wings extending outwardly therefrom. Each arm 12 is somewhat flattened at its outer portion, as at 14, and to one side of the flattened portion of each arm a sheet metal member 15 of suitable gage, or a. thinly forged member is secured by means of rivets 16. The sheet metal or thinl forged members are shaped to the desire pitch transversely, and by reason of their attachment to the arms 12 of the metallic central ortion, these arms and sheet metal or thin y forged members constitute metallic foundation pieces.

The sheet metal or thinly forged members are preferably stifl'ened or reinforced to assure retention of the pitch to which they are shaped, and this is done preferably b formin openings 17 in the metal and bending or orging the marginal portions of the metal foundation around these openings forwardly or rearwardly, as may be desired, so as to form stiffening ribs or flanges 18. These stifiening ribs or flanges are therefore integral with the body portion of the metallic foundation pieces and they trend both longitudinally, as at 19, and transversely, as at 20. These 0 enings are formed in the sheet metal or t inly forged portions of the foundation ieces in a plurality of re ions so that said ribs or flanges are forme in sets arranged succes ively greater distances from the axis of the propeller, the outer transverse ribs or flanges of each set being spaced from the inner transverse ribs or flanges of each adjacent set.

Between the ribs or flanges of each 0 ening I insert fillers 21 of soft wood, w ich are glued or otherwise fastened at their edges to said ribs or flanges. Similar fillers 22 are placed between the longitudinal ribs or flanges of adjoining openings in each set, and fillers 23 of like material are placed between the adjacent transverse flanges of adjacent sets of openin s; also between the transverse flan es of t e innermost set of openings and t e outer end of the arms 12 ofthe metallic central portion 10, as at 24. The various fillers described have opposite faces thereof flush respectivel with one side of the sheet metal or thinly or' d foundation pieces and with the edges 0 the ribs or flanges extending from the other side thereof, and in order to provide a smooth surface from the outer lon itudinal ribs or flanges of each set to the or? es of the sheet metal or thinly forged foun ation pieces, marginal filler-pieces 25 are glued or otherwise fastened to the foundation pieces, said margi nal filler pieces 25 extending, if desired, be; yond the edges of said sheet metal or thinly 95 forged foundation pieces, as shown at 26, in Figs. 5 and 7.

By the use of these filler pieces, glued or otherwise applied to the foundation members, opposite sides of said foundation mem- 100 bers are perfectly smooth, and these metallic foundation pieces having the soft wood fillers or filler pieces applied thereto furnish a foundation to which wooden exterior or facing' members ma be conveniently glued, and 106 in the drawings have shown a wooden facing member 27 glued or otherwise fastened to one side of the wood-filled metallic foundation piece and a wooden facing member 28 glued or otherwise applied to the other 110 side thereof. These facing members are constructed of mahogany .or other suitable wood and have substantially the same pitch as the foundation pieces, but their outer faces'are worked to desired contour with the 115 marginal portions of the wing formed to sharp edges. Throughout the greater portion of the length of each blade, one side of ,the wing thus formed is somewhat concave transversely and the other side cannot readily become warped out of its effective pitch, and which will not easily become split, although it will not be found necessary to build up the wing with the great number of layers of wooden members now necessarily employed.

While I have shown the metallic members 15 straight-lined transversely, it will be clear that the general pitch of the wing may be maintained even though said foundation pieces were to be curved, either to conform to the curvature of the concave exterior of the blade or to the curvature of portions of said arms, and when these wooden facing members are shaped to desired form, the tapered marginal portions of one of the members are sheathed or boundwith thin sheet copper or other suitable sheet metal fashioned into substantially V-shape so as to fit the tapered marginal portions of the wing. The wooden facing member to which the metallic sheathing or binding material is applied is grooved at regular intervals around the same, as at 31, on both sides thereof, preferably equal distances from the sharp edge thereof, the grooves at one side of the facing member being staggored with reference to those at 'the other side thereof, and the sheet copper or other sheet metal material when ap lied to the wing has parts thereof force into these grooves, as at 32. ,This sheet metal material is provided with perforations 33, which are adapted to register with holes 34 formed in the facing member to which the sheathing is supplied.

A fastening medium in the form of a flexible wire 35 is threaded back and forth through the perforations in the sheathing or binding and'the holes in the facing memher whch register with said perforations, the wire being entered in the depressed ortions of the copper at opposite sides an beingconcealed by a sealing medium 36 placed into the depressed portions of the sheathing or binding so that the exterior of the sheathing or binding is perfectly smooth throughout. In order that this metallic sheathing or bindjn material is flush with the exterior faces of t e wooden facing members of the propeller wings, the metal is well hammered agamst the wooden members to which it is applied, and the edges thereof are forced into said Wooden members. The crevices thus created at said edges are filled with sealing material. To the ropeller thus formed, the usual layer of linen or other fabric material may be ap lied so as to conceal all joints and the wiiole may then be painted or varnished, or the propeller may e otherwise finished so that the exterior is perfectlg smooth and presents no irregularities to t e air through which it is rotated.

In the modification shown in Fig. 10, the section of which is taken on a plane through one of rivetslfi of Fig. 4, the wing is faced with suitable armor late 37, which is intended-to cover the wing from the tip there of to the extreme inner end of the wooden facin members coverin the metallic foun ation of the wing. s clearly shown in Fig. 10 this armor plate conforms to the shape of the wing and covers the entire wooden exterior thereof so that a propeller thus constructed is practically bullet and shrapnel proof and is particularly adapted for use in warfare.

This improved propeller is of the simplest and most inexpensive construction, and it is nevertheless effective inits action. It is apparent that widely different embodiments of this invention could be made and the construction varied in many ways without departingl from the spirit of the invention, and it is t erefore my intention that the disclosure herein made should be considered illustrative and not applied in a limiting sense. Y o

It is further to be understood that the lanage employed in the following claims is lntended to cover all the generic and specific features of my invention herein described and shown in the accompanying drawings, and that no undue limitation should be understood-therefrom. The appended claims are therefore to be construed as broadly as permissible in view of the prior art.

Having thus described my invention, what I claim 1s: v

1. A propeller comprising a metallic foundation member shaped to the desired pitch, and wooden facing members secured to op osite sides of said foundation member and fiiiished to desired contour.

2. A propeller comprising a comparatively heavy metallic cditral member, comparatively thin metallic ieces secured to sand metallic central mem er, and wooden facin members secured to opposlte sides of said thin metallic pieces and to portions of the opposite sides of said metallic central member.

3. A propeller comprising a forged, central member having a hub and integral arms extending in op osite directions therefrom, comparatively t in metallic members socured to said arms, said arms and said thin metallic members being formed tddesired pitch, and wooden facing members secured to said thin metallic members and to the arms of said forged central member.

a 4. A propeller comprising a metallic foundation having the outer ortions there of comparatively thin and sti ened both longitudinally and transversely, and wooden acing members secured to said thin outer portions.

.5. A propeller comprising a metallic foundation having the outer portions thereof comparatively thin and stiffened longitudinally.

6. A propeller comprising a metallic foundation having the outer portions thereof comparatively thin and stiffened transverse] a 7 1i propeller comprising a metallic foundation piece having two wing members, the outer portion of each wing member being comparativel thin and provided with openings having anges extending from said openings, fillers fitting within said openings, and wooden facing members secured to opposite sides 'of said wing members.

ropeller comprising a comparatively thick metallic central member having oppositely-directed arms, the outer portions of said arms being flattened and arranged at an angle, comparatively thin metallic mem-v bers secured to the flattened outer ends of said arms and havin substantially the out line of the completed wing and the pitch of the same, each of said thin metallic members having openings therein and flanges extending from said openings, wooden fillers secured within said openings and between the flanges of adjoining openings, and wooden facing members secured to opposite sides of the wood-filled thin metallic members.

9. A. propeller comprising a comparatively thick metallic central member having 0 positely-directed arms, the outer portions 0? said arms being flattened and arranged at an angle, comparatively thin metallic members secured to the flattened outer ends of said arms and havin substantially the outline of the comp'letef wing and the pitch of the same, each of said thin metallic members having a plurality of sets of openings 'therein and flanges stamped therefrom and surrounding each open'm g, wooden fillers within each of said openings, filling pieces between the flanges of adjoining openings of each set and the adjacent flanges of adj acent sets of openin and filler 'pieces between the ed of said thin metallic member and the a jacent outer flanges of each set of openings, said fillers an filler pieces being flush with the edges of the flanges of said openings, and facing members secured to opposite sides of said thin metallic members.

10. A propeller comprising a metallic foundation having a hub and opposite wing members, the outer portions of said'opposite wing members being. thin and comparatively flat with both longitudinal and transverse stiffening means and openings surrounded by said stiffening means, wooden fillers within said ofpenings and around the same, and wooden acing members secured to the opposite sides of the wood-filled metallic thin outer portions of said wing members, the facing member at one side being convex and that at the other side concave with the outer faces meeting to form sharp edges around the wing.

11. A propel er comprising a forged metallic central ortion having a hub and opposite arms, t e outer ortions of said arms ein flattened and pitched, thin metallic mem ers secured to one side of the flattened portions of said arms and having openings therein and stiffening means extending from one side of said thin metallic members, said stiffening means surroundin said openings with the degree of extension t ereof equaling the thickness of the flattened outer portions of said arms, soft wood fillerelements within said openings. and around said stiflening means and being flush with the outer edges of said stiffening means and the flat outer portions of said arms, and wooden facing members secured to o posite sides of the thin metallic wood-filled members and to opgosite sides of sald arm and being shaped to esired form with the edges thereof sharp.

12. propeller comprising two wings, each wing being pitched to desired form and having a concave side and a convex side meetin to form sharp edges for the wing, regular =y-spaced holes formed throu h the wing along the marginal portion t ereof with grooves connectin ad'aieent holes alternatel at op osite sides oi the win a thin meta lic bin or applied to the marginal portion of each wing and having apertures registering'with said holes, the metal between ad acent airs of apertures at each side of the bin or bein pressed into the grooves of the wing, an wire passed back and forth through the apertures and holes and layin within the depressed portions of the meta ic binder, an means for completel filling said depressions to provide a smooth surface at each side of the wing.

In testimony whereoffilfigix ature. 

